Plasminogen Activator Levels Research Articles

Anticoagulant and fibrinolytic blood systems in patients with arterial hypertension stage III

Aim. To measure the indicators of the anticoagulant and fibrinolytic blood systems activity in patients with arterial hypertension after suffering a hemorrhagic stroke. Methods. 82 patients with arterial hypertension were examined at different terms after suffering a hemorrhagic stroke. Antithrombin III activity, total blood fibrinolytic activity and D-dimer levels, as well as tissue plasminogen activator activity and antigen levels were studied. Patients were examined at admission before standard treatment initiation and at discharge. Tissue plasminogen activator activity and its antigen level were determined at admission. Statistical data processing was performed using Statistica 8 (StatSoft) integrated package for Windows. Results. Inhibited fibrinolytic activity and an imbalance of its components, as well as reduced levels and activity of antithrombin III and signs of fibrin formation were revealed in patients with arterial hypertension stage III at different periods after suffering hemorrhagic stroke. Changes were most evident in early and late recovery periods after suffered cerebral stroke. Subsequent follow-up for over-a-year term after suffered cerebral stroke revealed a trend for normalization of these indicators. The study of tissue plasminogen activator activity and levels of its antigen showed significant changes in these parameters. Analysis of the obtained results for all patients with hypertension, regardless of the period of hemorrhagic stroke, showed the reduction of the antigen tissue plasminogen activator level and its increased activity. After in-patient treatment, there was a trend for improvement in all studied parameters without their complete normalization. Conclusion. The results suggest an activation of intravascular clotting in parients with arterial hypertension who suffered a hemorrhagic stroke, increasing the risk for further cardiovascular complications.

11-epi-Sinulariolide acetate reduces cell migration and invasion of human hepatocellular carcinoma by reducing the activation of ERK1/2, p38MAPK and FAK/PI3K/AKT/mTOR signaling pathways.

Cancer metastasis is one of the major causes of death in cancer. An active compound, 11-epi-sinulariolide acetate (11-epi-SA), isolated from the cultured soft coral Sinularia flexibilis has been examined for potential anti-cell migration and invasion effects on hepatocellular carcinoma cells (HCC). However, the molecular mechanism of anti-migration and invasion by 11-epi-SA on HCC, along with their corresponding effects, remain poorly understood. In this study, we investigated anti-migration and invasion effects and the underlying mechanism of 11-epi-SA in HA22T cells, and discovered by trans-well migration and invasion assays that 11-epi-SA provided a concentration-dependent inhibitory effect on the migration of human HCC HA22T cells. After treatment with 11-epi-SA for 24 h, there were suppressed protein levels of matrix metalloproteinase-2 (MMP-2), matrix metalloproteinase-9 (MMP-9) and urokinase-type plasminogen activator (uPA) in HA22T cells. Meanwhile, the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) and metalloproteinase-2 (TIMP-2) were increased in a concentration-dependent manner. Further investigation revealed that 11-epi-SA suppressed the phosphorylation of ERK1/2 and p38MAPK. The 11-epi-SA also suppressed the expression of the phosphorylation of FAK/PI3K/AKT/mTOR pathways.

No increased systemic fibrinolysis in women with heavy menstrual bleeding

Bleeding disorders have been recognized as important etiologic or contributory factors in women with heavy menstrual bleeding. Fibrinolysis in the endometrium plays a role in heavy menstrual bleeding. It is unknown whether increased systemic fibrinolysis might also increase the risk of heavy menstrual bleeding. To investigate fibrinolytic parameters, including clot lysis time, in women with heavy menstrual bleeding. We included 102 patients referred for heavy menstrual bleeding (Pictorial Bleeding Assessment Chart score of > 100) in our cohort. Patients and controls (28 healthy volunteers without heavy menstrual bleeding) underwent hemostatic testing in the first week after menstruation. For 79 patients and all controls, fibrinolytic parameters (thrombin-activatable fibrinolysis inhibitor activity, and plasminogen activator inhibitor-1, tissue-type plasminogen activator and plasmin inhibitor levels) and clot lysis time were available. Fibrinolytic parameters were similar between patients and controls, except for thrombin-activatable fibrinolysis inhibitor (89.4% vs. 82.5%) and plasmin inhibitor (106% vs. 96%), the levels of which which were significantly higher in patients. In women with menorrhagia without gynecologic abnormalities, we found lower thrombin-activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 levels than in women with gynecologic abnormalities (thrombin-activatable fibrinolysis inhibitor, 85.4% vs. 94.8%; plasminogen activator inhibitor-1, 16.0 μg L(-1) vs. 24.5 μg L(-1) ). Systemic fibrinolytic capacity is not increased in women with heavy menstrual bleeding. Overall, levels of the fibrinolytic inhibitors thrombin-activatable fibrinolysis inhibitor and plasmin inhibitor were even higher in patients than in controls. However, in a subgroup of women without gynecologic abnormalities, relatively lower levels of inhibitors may contribute to the heavy menstrual bleeding.

Levonorgestrel decreases tissue plasminogen activator levels through the androgen receptor in human endometrial endothelial cells

Heavy menstrual bleeding (HMB) affects almost 18 million women in the United States, leading to a loss of quality of life and decreased productivity. The Levonorgestrel Intra Uterine System is a highly effective first line treatment in reducing blood loss in HMB. However, the exact mechanism by which it affects the coagulation cascade remains unknown. The plasminogen activator system is an important pathway that controls fibrin clot formation and dissolution through regulation of plasmin. Very little is known about the role of this system in HMB.

Changes of serum parameters of TiO2 nanoparticle-induced atherosclerosis in mice

The evaluation of toxicological effects of nanoparticulate matter is increasingly important due to their growing occupational use and presence as compounds in consumer products. Numerous studies have shown that exposure to nanosized particles lead to systemic inflammation in experimental animals, but whether long-term exposure to nanosized particles induces atherogenesis is rarely evaluated. In the current study, mice were continuously exposed to TiO2 nanoparticles (NPs) at 1.25, 2.5, or 5mg/kg body weight, administered by nasal instillation for nine consecutive months, and the association between serum parameter changes and atherosclerosis in mice were investigated. The present findings suggested that chronic exposure to TiO2 NPs resulted in atherogenesis coupling with pulmonary inflammation, increased levels of serum triglycerides, glucose, total cholesterol, low-density lipoprotein cholesterol, advanced glycation end products, reactive oxygen species, NAD(P)H oxidases 4, C-reaction protein, E-selectin, endothelin-1, tissue factor, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, monocyte chemoattractant protein-1, plasminogen activator inhibitor-1, and reduced levels of serum high-density lipoprotein cholesterol, nitric oxide and tissue plasminogen activator. Our study suggests an association of long-term exposure to TiO2 NPs with atherosclerosis and pulmonary inflammation. This finding demonstrates the hypothesized role of TiO2 NPs as a risk factor for atherogenesis.

The Effect of Composition, Size, and Solubility on Acute Pulmonary Injury in Rats Following Exposure to Mexico City Ambient Particulate Matter Samples

Particulate matter (PM)-associated metals can contribute to adverse cardiopulmonary effects following exposure to air pollution. The aim of this study was to investigate how variation in the composition and size of ambient PM collected from two distinct regions in Mexico City relates to toxicity differences. Male Wistar Kyoto rats (14 wk) were intratracheally instilled with chemically characterized PM10 and PM2.5 from the north and PM10 from the south of Mexico City (3 mg/kg). Both water-soluble and acid-leachable fractions contained several metals, with levels generally higher in PM10 South. The insoluble and total, but not soluble, fractions of all PM induced pulmonary damage that was indicated by significant increases in neutrophilic inflammation, and several lung injury biomarkers including total protein, albumin, lactate dehydrogenase activity, and γ-glutamyl transferase activity 24 and 72 h postexposure. PM10 North and PM2.5 North also significantly decreased levels of the antioxidant ascorbic acid. Elevation in lung mRNA biomarkers of inflammation (tumor necrosis factor [TNF]-α and macrophage inflammatory protein [MIP]-2), oxidative stress (heme oxygenase [HO]-1, lectin-like oxidized low-density lipoprotein receptor [LOX]-1, and inducibile nitric oxide synthase [iNOS]), and thrombosis (tissue factor [TF] and plasminogen activator inhibitor [PAI]-1), as well as reduced levels of fibrinolytic protein tissue plasminogen activator (tPA), further indicated pulmonary injury following PM exposure. These responses were more pronounced with PM10 South (PM10 South > PM10 North > PM2.5 North), which contained higher levels of redox-active transition metals that may have contributed to specific differences in selected lung gene markers. These findings provide evidence that surface chemistry of the PM core and not the water-soluble fraction played an important role in regulating in vivo pulmonary toxicity responses to Mexico City PM.

Hyperglycemia is associated with lower levels of urokinase-type plasminogen activator and urokinase-type plasminogen activator receptor in wound fluid

AimsWounds in patients with hyperglycemia show impaired healing. Plasminogen activation is crucial in several overlapping phases of wound healing process. In this study, we aimed i) to compare acute wound fluid in patients with hyperglycemia and normoglycemia, ii) to focus on the elements of plasminogen activation in the wound fluid, and iii) to determine if the acute wound fluid characteristics are associated with surgical site infections. MethodsIn a cohort of 54 patients, a closed suction drain was placed in the wound above the anterior abdominal wall fascia under the skin in order to collect postoperative acute wound fluid samples for 3 following days after colorectal surgery. Patients were classified as normoglycemic (n=25) or hyperglycemic (n=29; 17 with type 2 diabetes and 12 with stress induced hyperglycemia). Surgical site infection was defined according to the Centers for Disease Control criteria. The levels of urokinase-type plasminogen activator (uPA), urokinase-type plasminogen activator receptor (uPAr), plasminogen activator inhibitor-1 (PAI-1), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and fibroblast growth factor-1 (FGF-1) were measured in the wound fluid. ResultsCompared to normoglycemic subjects, patients with hyperglycemia had significantly lower levels of uPA and uPAr in the wound fluid despite similar or even higher circulating levels. There was no significant difference in IL-1β, TNF-α, PAI-1 and FGF-1 levels. In the whole study population, the wound fluid levels of uPA and uPAr were negatively correlated with circulating glucose levels. No difference was detected in the wound fluid characteristics of patients with and without surgical site infection. ConclusionPatients with hyperglycemia exhibit decreased levels of uPA and uPAr in the wound fluid, suggesting a local failure in plasminogen activation at the wound site.

Prevention of experimental postoperative peritoneal adhesions through the intraperitoneal administration of tanshinone IIA.

Postoperative adhesions develop after nearly every abdominal surgery. The formation of adhesions is associated with the inflammatory response, fibrinolytic system, and extracellular matrix deposition in response to injury. Tanshinone IIA is one of the major extracts obtained from Salvia miltiorrhiza, which has anti-inflammatory effects on many diseases. Postoperative adhesions were induced by injuring the parietal peritoneum and cecum in Wistar rats, followed by the administration of various dosages of tanshinone IIA. The adhesion scores for each group were collected seven days after the initial laparotomy. The activity of the tissue-type plasminogen activator in the peritoneal lavage fluid was measured. The messenger ribonucleic acid expression levels of the tissue-type plasminogen activator, plasminogen activator inhibitor-1, and cyclooxygenase-2 in the ischaemic tissues were measured by quantitative real-time polymerase chain reaction. The intraperitoneal administration of tanshinone IIA is effective for the prevention of the formation of postoperative adhesions in rats. Tanshinone IIA increased fibrinolytic activity in the peritoneal lavage fluid and tissue-type plasminogen activator messenger ribonucleic acid expression in ischaemic peritoneal tissues but decreased the plasminogen activator inhibitor and cyclooxygenase-2 messenger ribonucleic acid expression significantly. These results revealed that tanshinone IIA was a potent postoperative adhesion preventer by enhancing fibrinolytic activity and decreasing cyclooxygenase-2 activity.

The Role of Plasminogen Activator Inhibitor-1 in the Metabolic Syndrome and Its Regulation

<p>Obesity is a major risk factor for cardiovascular disease (CVD). Lipid abnormalities, hypertension, impaired glucose tolerance or diabetes, are cardiovascular risk factors that are frequently present in patients with obesity. Haemostatic and fibrinolytic disturbances are also considered to be important risk factors for CVD hence, a potential link between CVD, obesity and the metabolic syndrome arises. Regulation of the fibrinolytic system can occur at the level of plasminogen activators and plasminogen activator inhibitor-1 (PAI-1). PAI-1, a glycoprotein, is one of the most important inhibitors of fibrinolysis. Regulation of this serine protease inhibitor may have a beneficial effect on other conditions associated with the metabolic syndrome. Human adipose tissue is a source of PAI-1. PAI-1 production may in turn be controlled by a number of hormones and cytokines which are secreted by adipose tissue in addition to dietary factors. In this review we summarise the current knowledge regarding the role of altered fibrinolytic function in obesity, CVD and hence the metabolic syndrome. Regulatory factors including different dietary components, weight loss and dietary intervention will also be discussed.</p>

Effect of lysine antifibrinolytics and cyclooxygenase inhibitors on the proteolytic profile of breast cancer cells interacting with macrophages or endothelial cells

Extracellular matrix (ECM) proteases play a key role in the regulation of tumour invasion, growth, and transendothelial migration. The expression of ECM proteases and their endogenous inhibitors by cancer cells is regulated by stromal cells. We investigated the effect of commonly used perioperative medications on this regulation. Breast cancer cells (4T1) were cultured alone or with endothelial cells (H5V) or macrophages (RAW264.7). Cell grown alone or in cocultures were treated with clinically relevant concentrations of cyclooxygenase (COX) inhibitors, aspirin (ASA), ketorolac, celecoxib, or lysine antifibrinolytics, ɛ-aminocaproic acid (EACA) and tranexamic acid (TXA). We determined the level of the ECM proteases urokinase-like plasminogen activator (uPA), matrix metalloproteinase (MMP)-2 and MMP-9, and endogenous MMP inhibitors, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in the conditioned media. Antifibrinolytics and COX inhibitors exerted a complex effect on cells grown alone and in cocultures. EACA increased the activity of MMP-9 and TIMP-1 in cocultures of 4T1 and RAW264.7. TXA increased TIMP-1 in the coculture without affecting MMP-9. EACA and TXA both attenuated MMP-2 detected in 4T1 and H5V cocultures. ASA and ketorolac both decreased the activity of MMP-2, MMP-9, and uPA. Celecoxib increased the activity of TIMP-1 in cocultures of 4T1 with both macrophages and endothelial cells. Antifibrinolytics and COX inhibitors can affect the proteolytic profile of the tumour microenvironment. Animal and clinical investigations are warranted to assess the effect of these proteolytic changes on the outcome of cancer surgery.

Lysis Onset Time as Diagnostic Rotational Thromboelastometry Parameter for Fast Detection of Hyperfibrinolysis

Rotational thromboelastometry is increasingly used to detect hyperfibrinolysis, which is a predictor of unfavorable outcome in patients with coagulation disturbances. In an in vitro study, the authors investigated which thromboelastometric hemostatic parameters could be valuable for fast diagnosis of the severity of hyperfibrinolysis and confirmed their findings in a patient population with hyperfibrinolysis. Thromboelastometry was performed after adding increasing concentrations of tissue plasminogen activator (0 to 400 ng/ml) to citrated blood samples of 15 healthy volunteers. Lysis parameters included the clotting time, maximum clot firmness, maximum lysis, and lysis onset time (LOT). The relation of tissue plasminogen activator with the LOT was further investigated in a patient population with out-of-hospital cardiac arrest and hyperfibrinolysis. The LOT showed a dose-dependent association with increasing tissue plasminogen activator concentrations. Late, intermediate, or fulminant hyperfibrinolysis was associated with an average LOT (mean ± SD) of 42.7 ± 13.8, 23.2 ± 8.2, and 17.5 ± 4.6 min in the in vitro study and estimated 42.2 ± 8.3, 29.1 ± 1.2, and 14.6 ± 7.7 min in patients, respectively. The authors found a moderately negative correlation between patient plasma tissue plasminogen activator levels and the LOT (r = -0.67; P = 0.01). This study shows that the LOT may be used for fast detection of severe hyperfibrinolysis, with a better resolution than the maximum lysis, and should be further evaluated for optimization of therapeutic strategies in patients with severe clot breakdown.

Modulation of uPA, MMPs and their inhibitors by a novel nutrient mixture in human glioblastoma cell lines

Brain tumors are highly aggressive tumors that are characterized by high levels of matrix metalloproteinase (MMP)-2 and -9 secretions that degrade the extracellular matrix (ECM) and basement membrane, allowing cancer cells to spread to distal organs. Proteases play a key role in tumor cell invasion and metastasis by digesting the basement membrane and ECM components. Strong clinical and experimental evidence demonstrates association of elevated levels of urokinase plasminogen activators (uPA) and MMPs with cancer progression, metastasis and shortened patient survival. MMP activities are regulated by specific tissue inhibitors of metalloproteinases (TIMPs). Our main objective was to study the effect of a nutrient mixture (NM) on the activity of uPA, MMPs and TIMPs in various human gliomas. Human glioblastoma (LN-18, T-98G and A-172) cell lines (ATCC) were cultured in their respective media and treated at confluence with NM at 0, 50, 100, 250, 500 and 1000 µg/ml. Analysis of uPA activity was carried out by fibrin zymography, MMPs by gelatinase zymography and TIMPs by reverse zymography. Glioblastoma cell lines LN-18 and T-98G expressed uPA, which was inhibited by NM in a dose-dependent manner. However, no bands corresponding to uPA were detected for the A-172 cell line. On gelatinase zymography, all three cell lines showed bands corresponding to MMP-2 and LN-18 and T-98G showed PMA (100 ng/ml)-induced MMP-9. NM inhibited their expression in a dose-dependent manner. Activity of TIMP-2 was upregulated by NM in all glioma cell lines in a dose-dependent manner. Analysis revealed a positive correlation between uPA and MMP-2 and a negative correlation between uPA/MMPs and TIMP-2. These findings suggest the therapeutic potential of NM in the treatment of gliomas.

Augmented expression of urokinase plasminogen activator and extracellular matrix proteins associates with multiple myeloma progression.

Multiple myeloma (MM) represents a B cell malignancy, characterized by a monoclonal proliferation of malignant plasma cells. Interactions between tumor cells and extracellular matrix (ECM) are of importance for tumor invasion and metastasis. Protein levels of urokinase plasminogen activator (uPA) and fibulin 1, nidogen and laminin in plasma and serum respectively and mRNA levels of these molecules in peripheral blood mononuclear cells were determined in 80 subjects by using ELISA and quantitative PCR and data was analyzed with severity of disease. Pearson correlation was determined to observe interrelationship between different molecules. A statistical significant increase for ECM proteins (laminin, nidogen and fibulin 1) and uPA at circulatory level as well as at mRNA level was observed compared to healthy controls. The levels of these molecules in serum might be utilized as a marker of active disease. Significant positive correlation of all ECM proteins with uPA was found and data also correlates with severity of disease. Strong association found between ECM proteins and uPA in this study supports that there might be interplay between these molecules which can be targeted. This study on these molecules may help to gain insight into processes of growth, spread, and clinical behavior of MM.

Analysis of Matrix Metallo-Proteases and the Plasminogen System in Mild Cognitive Impairment and Alzheimer's Disease Cerebrospinal Fluid

The expression of matrix metallo-proteases (MMP-2, MMP-3, MMP-7, and MMP-9), plasminogen and their regulators (TIMP-1, tissue plasminogen activator and neuroserpin) was investigated in cerebrospinal fluid (CSF) from subjective cognitive impairment (SCI) subjects, mild cognitive impairment (MCI), and Alzheimer's disease (AD) cases. ELISA analysis revealed a significant increase in MMP-3 protein levels in CSF from AD subjects, compared to age-matched SCI and MCI cases. No significant differences in MMP-2 and MMP-9 protein levels were detected between the three groups. MMP-7 was undetectable in all three groups. MCI individuals exhibited increased levels of the metallo-protease inhibitor TIMP-1 in CSF as well as higher plasminogen and neuroserpin expression, compared to SCI subjects. Levels of tissue plasminogen activator (tPA) were significantly reduced in AD CSF. Correlation analysis revealed a significant positive association between MMP-3, p-tau, and total-tau levels. Conversely, there was a significant negative correlation between this protease and Mini-Mental State Examination (MMSE) scores. tPA positively correlated with amyloid-β levels in CSF and with MMSE scores. Our results suggest that MMP-3 and tPA, in combination with current amyloid-β and tau biomarkers, may have potential as surrogate indicators of an ongoing AD pathology.

The neurokinin 1 receptor regulates peritoneal fibrinolytic activity and postoperative adhesion formation

BackgroundIntra-abdominal adhesions are a common source of postoperative morbidity. Previous studies in our laboratory have shown that a neurokinin 1 receptor antagonist (NK-1RA) reduces abdominal adhesion formation and increases peritoneal fibrinolytic activity. However, the cellular pathway by which the antagonist exerts its effects is unclear, as cultured peritoneal mesothelial cells exposed to the NK-1RA show increases in fibrinolytic activity despite having very low expression of neurokinin 1 receptor (NK-1R) messenger RNA and protein. Our aim was to determine whether the NK-1R plays an essential role in the adhesion-reducing effects of the NK-1RA, or if the NK-1RA is acting independently of the receptor. MethodsHomozygous NK-1R knockout mice and age matched wild-type mice underwent laparotomy with cecal cautery to induce adhesions. At the time of surgery, mice received a single intraperitoneal dose of either NK-1RA (25 mg/kg) or saline alone. Adhesion severity at the site of cecal cautery was assessed on postoperative day 7. In a separate experiment, peritoneal fluid was collected from wild type and NK-1R knockout mice 24 h after laparotomy with cecal cautery and administration of either NK-1RA or saline. Tissue plasminogen activator levels, representative of total fibrinolytic activity, were then measured in peritoneal fluid. ResultsIn wild-type mice, NK-1RA administration significantly decreased adhesion formation compared with saline controls. Among the NK-1R knockout mice, there was no significant reduction in adhesion formation by the NK-1RA. Fibrinolytic activity increased 244% in wild-type mice administered NK-1RA compared with saline controls; however, the NK-1RA did not raise fibrinolytic activity above saline controls in NK-1R knockout mice. ConclusionsThese data indicate that the NK-1R mediates the adhesion-reducing effects of the NK-1RA, in part, by the upregulation of peritoneal fibrinolysis, and suggest that the NK-1R is a promising therapeutic target for adhesion prevention.

Evaluation of gingival crevicular fluid levels of tissue plasminogen activator, plasminogen activator inhibitor 2, matrix metalloproteinase‐3 and interleukin 1‐β in patients with different periodontal diseases

The purpose of this study was to evaluate the gingival crevicular fluid levels of interleukin-1beta (IL-1β), matrix metalloproteinases-3 (MMP-3), tissue type plasminogen activator (t-PA) and plasminogen activator inhibitor 2 (PAI-2) in patients with chronic periodontitis, aggressive periodontitis (AgP) and healthy individuals (controls). Systemically healthy (21 chronic periodontitis, 23 AgP and 20 controls) subjects were included in this study. Plaque index, gingival index, probing pocket depth and clinical attachment level were recorded and gingival crevicular fluid samples were collected. Assays for IL-1β, MMP-3, t-PA and PAI-2 levels in gingival crevicular fluid were carried out by an enzyme-linked immunosorbent assay. The one-sample Kolmogorov-Smirnov test, Mann-Whitney U test and Spearman correlation coefficient were used for data analyses. Gingival crevicular fluid levels of t-PA and IL-1β were significantly higher in chronic periodontitis and AgP groups than in the control group (p<0.001). MMP-3 levels in gingival crevicular fluid were detected as significantly higher in the chronic periodontitis and AgP groups compared with the control group (p<0.05). The t-PA/PAI-2 rate of patients with chronic periodontitis and AgP were significantly higher than the control group (p<0.05). The positive correlations were found among the PAI-2, t-PA, IL-1β and MMP-3 levels in gingival crevicular fluid. The volume of the gingival crevicular fluid correlated with all of the clinical parameters (p<0.001). There were positive correlations between the gingival crevicular fluid levels of PAI-2 and the probing pocket depth and between gingival crevicular fluid levels of PAI-2 and the clinical attachment level (p<0.01). Similarly, significant correlations were found between t-PA levels and probing pocket depth and between t-PA levels and clinical attachment level measurements (p<0.001). The present data showed that gingival crevicular fluid levels of IL-1 β, MMP-3 and t-PA increased in periodontal disease regardless of the periodontitis type and played a part in tissue destruction.

L‐Mimosine and Dimethyloxaloylglycine Decrease Plasminogen Activation in Periodontal Fibroblasts

The use of prolyl hydroxylase inhibitors such as l-mimosine (L-MIM) and dimethyloxaloylglycine (DMOG) to improve angiogenesis is a new approach for periodontal regeneration. In addition to exhibiting pro-angiogenic effects, prolyl hydroxylase inhibitors can modulate the plasminogen activator system in cells from non-oral tissues. This study assesses the effect of prolyl hydroxylase inhibitors on plasminogen activation by fibroblasts from the periodontium. Gingival and periodontal ligament fibroblasts were incubated with L-MIM and DMOG. To investigate whether prolyl hydroxylase inhibitors modulate the net plasminogen activation, kinetic assays were performed with and without interleukin (IL)-1. Moreover, plasminogen activators and the respective inhibitors were analyzed by casein zymography, immune assays, and quantitative polymerase chain reaction. The kinetic assay showed that L-MIM and DMOG reduced plasminogen activation under basal and IL-1-stimulated conditions. Casein zymography revealed that the effect of L-MIM involves a decrease in urokinase-type plasminogen activator activity. In agreement with these findings, reduced levels of urokinase-type plasminogen activator and elevated levels of plasminogen activator inhibitor 1 were observed. L-MIM and DMOG can reduce plasminogen activation by fibroblasts from the gingiva and the periodontal ligament under basal conditions and in the presence of an inflammatory cytokine.

Regional variation in the secretory function of visceral fat depots from severely obese women (688.4)

Because of its hepatic venous drainage, visceral fat accumulation is an important risk factor for obesity‐related metabolic complications. Objective: To examine the secretory function of a properitoneal fat, the round ligament (RL) in severely obese women. Methods: Metabolic biomarkers, adipogenic, pro‐ vs. anti‐inflammatory, and prothrombotic characteristics were assessed in the RL adipose tissue (AT), and compared to visceral depots, the omental (OME) and mesenteric (MES) fat, in forty‐eight severely obese women (BMI, 54 ± 11 kg/m2), aged 38 ± 9 yrs. Expression of key enzymes involved in lipid metabolism (lipoprotein lipase, LPL; hormone‐sensitive lipase, HSL and phosphodiesterase‐3B, PDE‐3B), and of adipogenic factors (peroxisome proliferator activated receptors‐γ1/2, PPAR‐γ1/2) was measured by real‐time PCR. AT mRNA levels of plasminogen activator inhibitor‐1 (PAI‐1), interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNF‐α) and adiponectin were also determined. Results: AT‐LPL mRNA levels were the highest in the RL depot (0.005&lt;p&lt;0.05), whereas HSL expression did not show regional variation. The highest PDE‐3B and lowest PAI‐1 mRNA levels were observed in the RL and MES fat (0.0001p&lt;0.05). The lowest IL‐6 and TNF‐α as well as the highest adiponectin and PPAR‐γ1/2 mRNA levels were found in the RL AT (0.0001&lt;p&lt;0.05). Conclusion: Despite its anatomic location in the intraabdominal cavity, RL should not be considered as a “classical” visceral AT, as some of its secretory characteristics may contribute to limit the deleterious impact of visceral fat.Grant Funding Source: Supported by the CIHR and CRIUCPQ

Suboptimal glycaemic control enhances the risk of impaired prothrombotic state in youths with type 1 diabetes mellitus

To estimate markers of prothrombotic state and endothelial dysfunction in youths with type 1 diabetes mellitus (T1DM) and investigate possible associations with anthropometric/demographic data, glycaemic control and lipid profile. In a cross-sectional design, we recruited 155 youths with T1DM and determined levels of plasminogen activator inhibitor-1-antigen (PAI-1-Ag), von Willebrand factor-antigen (vWF-Ag), fibrinogen (FB), lipids and glycosylated haemoglobin (HbA1c). Of all the participants, 76 (49%) had increased levels of at least one of prothrombotic factors. Suboptimal glycaemic control was associated with a worse lipid profile and an eightfold increased risk of elevated vWF-Ag levels. Higher vWF-Ag concentrations were also correlated with impaired lipid profile and increased HbA1c values, whereas PAI-1-Ag was positively correlated only with triglyceride levels. After adjustment for potential confounders, only HbA1c contributed independently to the variation in vWF-Ag levels. Impaired prothrombotic state and consequently endothelial dysfunction are present in youths with T1DM, representing a cumulative risk factor for future cardiovascular disease (CVD). Achievement and maintenance of euglycaemia and normolipidaemia are crucial to decelerate progress of this process.

Inhibition of urokinase-type plasminogen activator expression by dihydroartemisinin in breast cancer cells.

The aim of the present study was to investigate the inhibitory effects of dihydroartemisinin (DHA) on the primary tumor growth and metastasis of the human breast cancer cell line, MDA-MB-231, in vitro. The expression levels of urokinase-type plasminogen activator (uPA) were detected by immunocytochemistry in two cell lines (MCF-7 and MDA-MB-231). The MDA-MB-231 cell activity was inhibited by various concentration gradients of DHA. The inhibitory rate, cell growth curve and apoptotic morphological observations were obtained using the MTT assay at 0, 24, 48 and 72 h. Cell scratch migration was performed at various time-points to test the cell proliferation and migration capacity. Reverse transcription-polymerase chain reaction was used to analyze the effect of DHA on uPA mRNA expression in breast cancer cells. The human breast cancer cell line, MDA-MB-231, possesses higher metastatic potential and relatively higher expression of uPA when compared with the MCF-7 cell line. DHA was found to inhibit the proliferation and migration capacity of the cell line, MDA-MB-231, in vitro. The growth inhibition occurred in a time- and dose-dependent manner, with IC50 values of 117.76±0.04, 60.26±0.12 and 52.96±0.07 μmol/l following 24, 48 and 72 h, respectively. The inhibition of uPA was observed to decrease breast cancer cell growth and migration. Thus, results of the present study indicate that DHA may be used for further studies with regard to breast cancer therapy.